This invention relates to an information terminal apparatus controlled by a microprocessor which is operated by a battery employed as an electric power source thereof.
Conventionally, this type of information terminal apparatus is provided with a battery voltage detecting circuit so as to prevent the microcomputer from malfunctioning due to a drop of battery voltage, when the battery capacity is lowering, and is constructed to stop the operation when a battery voltage drop is detected by the detecting circuit.
Also, for solving an inconvenience that a voltage drop causes a sudden stoppage of the apparatus, the information terminal apparatus is provided with a circuit for detecting a drop of battery capacity at a time when a bit of voltage capacity still remains so as to display such a battery capacity drop on a display unit or the like for warning. The conventional information terminal apparatus can also solve the inconvenience of a sudden stoppage thereof by coping with a battery capacity drop in two different manners, i.e., displaying a warning and stopping the apparatus.
However, when the information terminal apparatus as mentioned above is being used for communications, there may be a case where the communication is desired to be continued, even if the display for warning a battery capacity drop is disregarded, because of emergency or high importance of the communication. In such a case, however, the communication may be eventually interrupted by a stoppage of the information terminal apparatus. When the apparatus once stops, it is necessary to exchange or recharge a battery. If the battery has been completely discharged, an initial discharge characteristic may not be obtained even with the recharged battery.